Vat-dye.



UNITED g qfingfENT OFFICE.

WILHELM BAUER, OF V OHWI'NKEL, NEAR ELBERFELD, AND .ALIliRED HERRE, OF ELBERFELD, GERMANY, ASSIGNORS TO FAR-BENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, A CORBORATION OF GERMANY.

Application filed November 8; 1910. Serial No. 591,276.

Patented July 11, 1911.

VAT DYE.

997,260. Specification of Letters Patent.

( No Drawing.

T 0 all tvhom it may concern:

Be it known that we, VVILHELM BAUER and ALFRED Henna, doctors of philosophy, chemists, citizens of the German .Empire, residing, respectively, at Vohwinkel, near Elberfeld, and Elberfeld, Kingdom of Prussia, Germany, have invented useful 1mprovements in New Vat Dyes, of which the following is a specification.

Our present invention relates to the manufaeture and production of new vat dyestuffs, which are obtained by condensing 1 molecule of a 2-arylido-3-keto-dihydro-L thionaphthene compound, especially 2-para dimethylaminoanilido 3 keto dihydro l thionaphthene, 2-par'a dimethylamino anilido 8 keto dihydro 5 chloro-l-thionaph t-hene with 1 molecule of l-anthrol.

Thenew dyes are after being dried and pulverized violet powders soluble in hot benzene with a violet-red coloration With'a deep red fluorescence, yielding with hydrosulfite and N OH vats dyeing cotton fast violet shad-s.

In-order to illustrate the new process more fully the following example is given, the parts being by wcight:'A hot solution in glacial acetic acid of 282 parts of 2-paraamino dimethylanilido 3 keto dihydro-lthionaphthene (obtainable from nitrosodimethylanilin and 3 oxy 1 thionaphthenc) and of 194- parts of l-anthrol is heated on the water bath for about hour. The process. proceeds most probably according to the 1 following equatlonz The dye which separates on cooling is substantially as described.

talline'- powder so'luble'in hot benzene with'a violet-red color with a deep red fluorescence 'andin concentrated sulfuric acid with a green color. By treatment with hydrosulfite and N OI-I a brownish yellow vat results.

from which cotton is dyed in pure fast violet shades.

. \Ve-claimz- 1. The herein described new vat dyestuffs containing in their molecule the group:

2. The herein described new vat dyestufi' having probably the formula: I

which dye is a, violet crystalline powder soluble in hot benzene with a violet-red color with a deep red fluorescence and in concentrated sulfuric acid with a green color;

yielding upon treatment with hydrosulfite and N OH a brownish-yellow vat from which cotton is dyed in pure, -fas'tiviolet shades, substantially as described.

In testimony whereof we have hereunto set-our hands in the presence of two subscribing witnesses.

WILHELM BAUER. 1... s]

ALFRED EL.

Vitnesses CHAS. J. VRIGHT, ALFRED HENKEL. 

